6. And Dan Drezner is certainly correct that Trump is a bonanza for political science research. The only problem? He’s not running a field campaign. And he’s not (so far at least) running ads. And he’s a terrible candidate. And he’s divided the party. And probably a few more I’m not thinking of right now. In other words, Trump will give us a new estimate -- assuming things continue as they are now, with much of it already locked in -- of the maximum “campaign and candidate” effect. But that won’t necessarily make it easier to investigate and untangle what goes into that large effect.

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